Blackveil Vaal Hazak

Effluvium Spores. The vaal hazak's body is covered with four white spore pods. Whenever a creature touches or hits the vaal hazak with an attack or spell, or when the vaal hazak uses its effluvium breath, it releases two spore clouds that fall to the ground in adjacent spaces next to the vaal hazak. The clouds fill a 10-foot square cube, spreads around corners, and its area is lightly obscured. It lasts for the 10 minutes or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. A creature that starts its turn in one of these clouds takes 11 (3d6) necrotic damage and must succeed on a DC 21 Constitution saving throw, or be cursed. While cursed in this way, the vaal hazak's attacks deal an extra 1d8 necrotic damage to the cursed creature. The white spore pods on the vaal hazak can be attacked and destroyed (AC 15; hp 30; vulnerability to fire damage; immunity to acid, poison, and psychic damage).

Legendary Resistance (3/Day). If the vaal hazak fails a saving throw, it can choose to succeed instead.

Magic Resistance. The vaal hazak has advantage on saving throws against spells and other magical effects.

Regeneration. The vaal hazak regains 30 hit points at the start of its turn if it has at least 1 hit point. If the vaal hazak takes radiant damage or damage from holy water, this trait doesn't function at the start of the vaal hazak's next turn.

Multiattack. The vaal hazak makes two Bite attacks and two Claw attacks.

Bite. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 24 (4d8 + 6) piercing damage.

Claw. Melee Weapon Attack. +14 to hit, reach 5 ft., one target. Hit: 20 (4d6 + 6) slashing damage.

Tail. Melee Weapon Attack. +14 to hit, reach 15 ft., one target. Hit: 28 (4d10 + 6) bludgeoning damage, and the target must make a DC 22 Strength saving throw or be knocked prone.

Effluvium Burst (Recharge 6). The vaal hazak lets out an ear shattering roar causing effluvium spores to erupt from its body in a 300-foot radius around that remains until the start of the vaal hazak's next turn. Each creature that starts its turn in that area, or enters it for the first time must make a DC 21 Constitution saving throw or become cursed for 1 minute. A creature that succeeds on its saving throw, is immune to this effect for 24 hours. While cursed in this way, the target must make a DC 21 Wisdom saving throw at the start of each of its turns. On a failed save, it is incapacitated until the start of its next turn. When the effluvium disperses at the start of the vaal hazak's next turn, all destroyed spore pods regrow on the vaal hazak and ten spore clouds remain in the area that are at least 20 feet apart from each other.

The vaal hazak can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The vaal hazak regains spent legendary actions at the start of its turn.

Tail Attack. The vaal hazak makes a Tail attack.

Siphon Curse (Costs 2 Actions). Each cursed creature within 60 feet of the vaal hazak must make a DC 21 Constitution saving throw, taking 21 (6d6) necrotic damage on a failed save, or half as much damage on a successful one. The cursed creatures's hit point maximum is reduced by an amount equal to the necrotic damage taken. The reduction lasts until the creature finishes a Long Rest.

Effluvium Fog Breath (Costs 3 Actions). The vaal hazak exhales a cloud of effluvium bacteria in a 90-foot cone. Each creature in that area must make a DC 21 Constitution saving throw, taking 70 (20d6) necrotic damage and be cursed 1 minute on a failed save, or half as much damage on a successful one and are not cursed. If a creature's saving throw is successful, the creature is immune to this curse for the next 24 hours. While cursed in this way, the creature has disadvantage on attack rolls against the vaal hazak.